Process of and apparatus for the manufacture and handling of metallic-leaf films



8. P. OLSON. PROCESS OF AND APPARATUS FOR THE MANUFACTURE AND HANDLINGOF METALLfC LEAF FILMS.

APPLICATAION man AUG.6. 1920. 1,387,068, v Patented Aug. 9, 1921,

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@51 tJ-t' OL'VLQAJ d? C. P. OLSON.

PROCESS OF AND APPARATUS FOR THE MANUFACTURE AND HANDLING OF METALLICLEAF FILMS.

APPLICATION FILED AUG.6- 1920.

Patented Aug. 9, 1921.

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Mk Mk AQN N E N C. P. OLSON. PROCESS OF AND APPARATUS FOR THEMANUFACTURE AND HANDLING OF METALLIC LEAF FILMS.

APPLICATION FILED AUGIGI I920.

Am m @M A m \N d w m s I m mm W P MN m O I m -K k/I n I M 1111 II AQIIQNI MN I I I I I R. Aw N %a a. k IQ mm Cu a B /VFW mm 3 I Q & w a I A A i1 @NEEEQ STATES CARL P. OLSON, OF IRVINGTON, NEW JERSEY.

rnocnss or AND ArrAnArus non ran MANUFACTURE AND HANDLING ormn'rAnrarest ornate.

DIG-LEAF FILMS.

essons."

Specification of Letters Patent.

Patented Aug. 9, 1921.

Application filed August 6, 1920. Serial No. 401,642.

T 0 all whom it may 001mm" Be it known that I CARL P. OLSON, acitizen ofthe United states, residing in the town of Irvington, county of Essex,and State of New Jersey, have invented certain new and usefulImprovements in Processes of and Apparatus for the Manufacture andHandling of Metallic-Leaf Films, of which the following is aspecification.

This invention relates to a process of manufacture of imitation gold orsilver leaf or the like and to apparatus for the practice of suchprocess, and for handling the leaf as produced, and to the improved leafobtained therewith.

Gold leaf is used extensively in the arts for embossing and 'gilding,and particularly for stamping titles and ornamentations upon bookcovers. Pure gold leaf, as so used, is of a thickness not greater thanone ten-thousandth of an inch. This degree of fineness is required inthe art to secure that frangibility of leaf requisite to produce sharplydefined margins when letters or other designs are stamped therefrom uponleather or other like substances by means of dies. It has been an objectlong sought to produce commercially a leaf in imitation of those of theprecious metals which should have as close an approximation as possibleto the extreme tenuity characterizing them, while also preserving therequisite opacity of the solid metal. Imitation metallic leaf has beenmade commercially, using bronze powder as the metallic base, of athinness of one four-thousandth (1)0025) of an inch. Such leaves havebeen made by coating a glass or the like surface with a volatile liquidas a carrier for the bronze powders held in suspension therein, thevolatile liquid being alsoa solvent of nitro-cellulose which, afterevaporation of the volatile solvent, remained with the bronze powdersand acted as a binder therefor. Such imitation metallic leavessimulating gold and silver leaf have been made either by painting,dipping or sprayin the glass or similar polished support, thinly to coatit with theleaf-forming material, comprising a binder of nitro-celluloseand bronze powders, the term bronze powders being generic to finelydivided base metals; also by floating the like suspenslon upon awater-bath. Leaves so made have surpassed in thinness those possible ofmanufacture by coating a sheet of tissue or the like permanent back tobe incorporated in the leaf, as Well as those built up from successivelayers of materials as by first coating a support with an adhesive andthen powdering the binding coat, as well as those made by heating orrolling thebase-metals. All the above recited processes also have theircommercial limitations as to size of leaf producible. One of the objectsof the present invention is the production upon a commercial scale ofimitation gold leaf in endless lengths as a continuous process withapparatus that functions automatically. 0nd object is the production ofa leaf of greater thinness than heretofore producible upon a commercialscale. Further objects sought are the production of a leaf which shallhave such a degree of opacity that the covering effect of the thickerleaf shall not be sacrificed, 'while the removal of the surplus materialafter embossing or stamping shall be easier and more certain by virtueof the extreme tenuity of the leaf, and shall render unnecessary eitherthe incorporation of any brittling agent to the leaf-forming mixture tofacilitate the clearing off of the surplus leaf, or the scrubbling whichbookbinders customarily are otherwise forced to resort to when the leafis tenacious. Other objects will be pointed out in the ensuingspecification.

To these ends, my invention consists, first, (in a rocess ofleaf-formation comprising essentially the steps (a) of overcoming thetendency of the heavier bronze powders to settle out of a leaf-formingsolution by counteracting the, effect of gravity upon the liquidsuspension; (7)) of applying this suspension, unusually rich in bronzeand of substantially unvarying homogeneity, as a coating of minimumthinness "to a film-forming carrier whereby a leaf is produced of greattenuity and opacity; (0) of accelerating the evaporation of the volatilesolvents by application of currents of heatedair to the coatmgato romotethe film-formation.

y mvention' consists, secondly,- in the provision of substantiallyautomatic means adapted to perform these several successive steps of theprocess, consisting essentiall of a source of power for driving thesevera operative elements constituting the apparatus of my invention intimed relation, respec- Asec-- tively as follows: A stirrer in a tank ofleafforming composition; a pump adapted to withdraw the compositiontherefrom and to supply it to a dipping roll which coats a movingcarrier; means for varying the speed of said roll; a film-forming drumengaging said roll and means for regulating the speed of said drum; aleaf-removing roll cooperating with said drum; all the foregoingelements being driven indirectly from the said source of power; andmeans for heating preferably dry air; means causing said aircurrents tocirculate over the drum, and to vary their volume and rate. In additionto the foregoing semi-automatic apparatus adapted to form and handle acontinuous film in unlimited lengths, my invention consists in means foradapting said apparatus to form and handle leaf of any desired width upto the width of the drum, whose width is a matter of commercial design;and in the provision of means for handling the formed film ready'forcutting in desired lengths.

My invention finally consists in the novel product resultant as a leafof unlimited length, of a thinness approximating one tenthousandth of aninch (.0001) and of a density and opacity simulating that of pure goldleaf, being characterized when viewed mlcroscopically by a dispositionof its con stituent bronze .resembling lamination of the flakyparticles, by unusual freedom from streaks, such as result from flowingon glass, and from. air-holes, such as result from floatmg on a bath,and from irregular distribution of the powder, such as results from theintermixture of non-volatile ingredients, and by unusual luster andbrilliance due to the high percentage of the metallic ingredientincorporated in the transparent binder.

In practising the above outlined process in its preferred form, I employthe apparatus illustrated in the accompanying drawings forming a part ofthis specification and 1n wh1ch Figure 1 shows in elevation andprincipally in vertical section a leaf-formmg and conveying apparatus.Fig. 2 is a' plan view on the line IIII of Flg. 1, the

' drum casing being broken away and underlying parts being shown bydotted outlines. Flg. 3 is a like View on the line III-III of Fig. 1,showing the mixing tank, the coatmg roll, the cleaning rolls, theremoval roll and conveyer. Fig. 4 is a vertical view, on the hue IV-IVof Fi 1, partly in section, showing the drum, t e conveyer and thedriving means for each and the removal roll. F i 5 is a vertical View,on the line V-V of ig. 1, and partly in section, showing the mlxlngtank, pump, supply tank, coating roll and drum. ig. 6 is a detail viewon the line VIVI of Fig. 1, showing one of the cleaning? rollscontacting with the drum. F ig. 7 isano ther detail view, on the line VIVII of Fig. 1, showing the steam-coil the means permittinginterchangeability of these rolls. The same reference numerals are usedto indicate the same or like parts throughout the several figures.

1 is a motor having upon its armature shaft the worm 2 meshing with thecogged wheel 3 whose shaft 4, suitably journaled in the framing of theapparatus, carries the cone-shaped member 5, over which runs the belt 6to and returning around a second coneshaped member 7, the pair beingreversely disposed to constitute a cone pulley adapted.

to vary the speed of its members by shipping of the belt by the shifter8. An extension of the shaft 4 carries the belt 9 which in turn rotatesthe shaft 10 which in turncarries the beltll which drives a shaft 12carrying the gear 13 engaging the bevel gear 14 mounted upon the shaft15 extending downwardly and carrying the pad-- dles 16 for agitating thecontents of the tank 17 having the outlet pipe 18 leading to the pump19, comprising a rotatable springpressed vane 20 adapted to withdrawfluid from said tank, the vane being rotated about a shaft driven by thebelt 21 from a pulley 22 upon the shaft 12. The pump 19 dischargesthrough the vertically extended pipe 23 which empties into a V-shapedtrough 24 having a return overflow connection 25 to the tank 17. Thesecond member 7, of the cone pulley, has a shaft .26, suitably journaledin a bearing 27 on the frame 28, and terminated by a sprocket drivingthe chain 29 engaging a driven wheel 30 upon the shaft 31 upon which ismounted the rotatable drying drum 32 having the hub 33, skeleton 34 andperiphery adapted to receive the film, 35. The shaft 31 also carries thesprocket wheel 36 by which the chain belt 37 is driven and in turndrives the sprocket 38 upon the shaft 39 which carries a drum 40suitably journaled in the frame. This drLun carries the conveyer or.belt 41, which passes around a second cylindrical drum 42, suitablymounted in the frame. The film-forming drying drum 32 is surrounded asto the upper two-thirds of its periphery by a housing 43 extending belowthe periphery and in closing and practically sealing same against entryof air by suitable edging 44 of felt or the like. The housing thusaffords a substantially closed chamber of diminishing height, the largerend terminating in a casing 45 surrounding a steam coil 50 havingsteam-connection 51 to a boiler not shown and a valved vent 52. An airdrying medium is preferably employed to dehydrate the air circulatingabout the coil 50 and through the housing 43 to the narrowed vent end,below the axial plane of the drum, where the'housing is terminated bypiping 53 connecting with and forming the entrance to a suction fan 54.The volatile fluid entering the casing as vapor at its larger end isunder suction, induced by the fan connected to the piping, which drawsthe volatiles through the housing at a rate increasing as the crosssectional area diminishes.

The shaft 10 carries the lower member 66 of a cone pulley, the uppermember of which, 67, is mounted on a shaft 68, a belt 69 con-- nectingthe two members. The front end of the shaft 10 is driven by the belt 9,and the rear end of the shaft 10 carries the belt 11, as beforedescribed; by shifting the belt 66, the rate of rotation of the stirrerand pump may be varied, the rate of the rotation of the shaft 68 beingvaried inversely by such shift of the shipper 70. Upon the shaft 68 isjournaled a frame 71, supported upon the adjusting screws 72, mounted inthe frame extensions 73. This rocking frame at its other end supportsthe coating roll 74 which is driven from the shaft 68 by the twistedbelt 75 so as to rotate the coating roll in the same direction as therotation of the drying drum 32. The shaft 10 also drives the belt 76which in turn drives a series of drum-engaging rolls 77, 78 and 79,likewise journaled in the frame. The rolls 77 and 7 8 are brushesadapted to be rotated by the belt 76 in reverse directions to wipe theperiphery of the drying drum. The roll 79 is a bufling roll, preferablyof felt, to dry and polish the drum. A box 80 incloses these rolls tocatch the dust or the like, if

any, removed by them. The speed of these rolls is controlled by thatmember of the cone pulley controlling the speeds of the stirrer and pumpto accord therewith and is varied inversely as the speed of the coatingroll which is controlled as to speed by the other member of the conepulley, for purposes hereinafter developed. At the lower quadrant of thedrum opposed to the coating roll is the take-off roll 81. This is a lazyroll, driven by peripheral contact with the film upon the drum. It ispreferably of felt and j ournaled in the frame over a trough 82 holdinga, wetting medium into which dip the rolls 83 journaled in the troughand which rolls contact with the roll 81, moisten-- ing it so that it inturn may adequately moisten the film which, when of cellulose base, willcontract away from the drum and pass down the rectangular chute 84 whicguides it to the conveyer.

The operation of the apparatus described is dissolvable commercially asdescribed in Letters Patent No. 992,743, in the ratio of two ounces ofsoluble cotton to three ounces of amylacetate and one pint of benzin, Iprefer to increase the ratio by employing two pintsof amylacetate to oneounce of cotton. The preferred proportions are, by weight, one ounce ofsoluble cotton, dry, and eight ounces of bronze powder of the gradeknown as finest pale gold, or, substantially 10 per cent. of cotton to90 per cent. of powder. This mixture is one that flows freely whensolvent of the cotton is in excess of the amount needed to effect itssolution. With this mixture, the speed of revolution of a drying drumfive feet in diameter should be approximately five feet per minute, orrevolution per minute, with a drying temperature between 150-180 Fahr.The belt 6 having been adjusted to deliver the correct rate ofdrum-rotation, the tilting table 71 is adjusted by the screws 72 so thatthe coating roll 74 affords a minimum clearance between its surface andthat of the drying drum 32. The film-forming periphery of this drum ispreferably of hard, polished material. In practice, burnished has beensuccessfully used with a coating roll of like metal. The temperaturehaving been established by the coils 50 and the suction fan 54 being inoperation, the belt 69 is initially regulated by hand, so that, with agiven solution the stirring and pumping may be more vigorous for a heavysolution, and the speed of the coating roll proportionally slower, therates adapted to produce the best results being matter determined by thefluidity of the leaf-forming mixture. This mutual dependence is due tothe discovery that a mixture high in bronze may be used to make a denserleaf if the suspension of the bronze is maintained during the coatingprocess. To this end, an active agitation of the mixture in the tank isnecessary and the pumping thereof from near the base of the tank isdesirable, as well as a pumping action that will drive the mixture up tothe roll in a constantly ascending column rich in suspended powder. Thisrich mixture is taken up by the coat ing roll, and due to its viscositya layer of the mixture adheres thereto of approximately one-fourth inchin depth, with which layer the drying drum contacts. By locating thecoating roll below the drum, the line of their closest approach is belowthe axial horizontal plane of the drum and above copper.

the axial horizontal plane of the roll, and this relative location ofthe two cylindrical surfaces permits gravity to act upon the layer ofsolution to thin it, and thus the desired object of yielding thethinnest possible continuous film is promoted. Other expedients, as bydipping the drying drum directly into the mixture or using-a coatingroll above the horizontal medial plane of the drum, result in thedeposit of superfluous material'which adheres to the drying surface anddesired. I

With a coating of the thinness attainable with the apparatus and by theprocess described, the film dries with great. rapidity under the currentof air whose volume is diminished as its rate of motion is acceleratedby the narrowing channel afforded by the form of the casing and thesuction of the fan, and is delivered as a ribbon-like sheet insubstantially endless length, to the conveyor upon which it is depositedas a continuous film, ready for cutting and immediate packaging withoutthe need of rehandling, as in the present practice. In lieu of aconveyer, the film may be received upon any suitable support, but Iprefer the conveyer shown, as it affords opportunity for inspection ofthe film and permits its readier control.

Having thus explained the principles of my invention and the best modenow known to me of applying same, and believing these principles to becapable of application by other means than those shown and described, Ido not wish to be understood as limiting the scope of my invention tothe structural embodiment of means illustrated, nor to the particularmethods of operation set forth, save as my preferred practice.

In the appended claims, the term leaft is employed to designate theimitation metallic leaf as used commercially, resulting from the cuttinup of the film to desired sizes; the term 1m is employed to denote thecontinuous web formed in endless length by the drying of the composiioncoated upon the film-forming drum; and the term coating to denote thecomposition as applied to the drum prior to hardening by evaporationinto'a film. It may also be noted that the term bronze powder is used inits generic sense.

Having thus described my invention, I claim:

1. The process of forming imitation metallic leaf as a continuous film,consisting in agitating a film-forming suspension of bronze-powder tosuch degree that the powder does not appreciably settle in thesuspending medium; dipping said suspension while in an agitatedcondition, applying produces a thicker-coating than same as acoating toa revolving surface on v a line lower than the axis of rotation of saidsurface, subjecting the coating so formed to a current of preheated air,and removing the resultant film while the surface is revolving.

2. The process of forming imitation gold leaf as a continuous film,consisting in agitating a film-forming suspension of bronze powder,delivering same while undergoing agitation to a rotating distributer,delivering same therefrom to a revolving surface, subjecting the coatingso formed to a current of preheated air and removing the dried coatingfrom said surface as a film of unlimited length.

3. The process of forming imitation goldleaf in unlimited lengthsconsisting in agitating a film-forming suspension of bronze powder,delivering same in an ascending stream to a distribute'r, coating sameupon a rotating surface, subjecting the coating so formed to a currentof preheated air, and removing the dried film from said surface as acontinuous film.

4:. The process of forming imitation goldleaf as a continuous film'ofunlimited length and of thinness and density approximating that ofgold-leaf, consisting in coating a rotating surface with a substantiallyhomogeneous and rich suspension of bronze-powder in a solution ofnitrocellulose, the proportion of solvent being largely in excess ofthat necessary to dissolve the nitrocellulose and the quantity of thepowder being by weight in excess of both, driving off the solvent with amoving volume of preheated air in contact with the surface of thecoating, causing the outer surface of the dried coating to contract bywetting, and continuously stripping said coating as a film from therotating surface. I

5. The process of making imitation metallic leaf from a suspension ofbronze powders in a solution of nitrocellulose, consisting in coating arevolving surface with the suspension, drawing a current of heated airover said coated surface at aconstantly accelerated rate of motion whilein contact with-said surface, and confining the air during its contactwith said surface.

6. In an apparatus for producing imitation metallic leaf, thecombination of a revolving film-forming drum, a motor adapted to drivesame and an adjustable speed-varying element between the two; afilm-composition tank having an agitator therein and a connection to apump adapted to withdraw the composition from said tank and to raise itto a reservoir adjacent said drum, and an overflow return from saidreservoir to said tank; a shaft driven indirectly by said motor and inturn driving a gearing operatively connected to said agitator. and tosaid pump and an adjustable speed-varying element between said shaft andsaid gearing; the two said speed-varying elements being mutuallyresponsive, and an adjuster adapted to control said elementssimultaneously.

7. In apparatus for produ cing imitation metallic leaf, in combination,a' film-forming revolving drum, means adapted to coat the periphery ofsaid drum with a film-forming solution, said means being located belowthe horizontal plane of the drum and including a pump adapted to causean ascending strgam of said solution to be supplied to said coatingmeans, a housing inclosing the upper half of said drum, a heating sourceadapted to supply superheated air to said housing, and meansadapted todraw said air from said heating source through said housing and incontact. with the film upon the periphery of said drum.

8. In an apparatus for making imitation metallic leaf, the combinationof means adapted to supply a film-forming solution continuously to theperiphery of a revolving drum as a thin coating, said means comprising arevolving cylinder the axis of which is parallel to the axis of the drumand the periphery of which is spaced apart from the periphery of saiddrum, with means adapted to revolve both said drum and said cylinder atindependently regulable speeds and means adapted to vary the spacingbetween the two peripheries, cylinder being of relatively small diameterand located below the horizontal axial plane of the drum andapproximately theregrom upon the upwardly moving side.of the rum.

9. In an apparatus for making imitation metallic leaf, the combinationof means adapted to supply a film-forming solution continuously in anagitated state to a revolving cylinder located adjacent to and busimitation metallic film as the said,

the suspension so dipped to a beneath a revolving cylindrical drum, theaxes of revolution of said cylinder and drum being parallel and adaptedto turn in the same direction, means adapted tovary the distance betweensaid axes, means for driving both, and a speed-controlling meansinterposed between said driving means and said drum and cylinder adaptedto vary their relative speeds inversely.

10. In apparatus adapted to form imitation metallic leaf as a continuousfilm, means adapted to coat a predetermined width of the periphery of arevolving drum with a film-forming solution containing a volatilesolvent, said drum and means for driving same at predetermined speed, asource of heated air, and means adapted to cause the circulation of saidair successively channel leading from through an inclosed over theperiphery of said heating source,

said drum, and through an exhaust in diminishing volume and at anincreasing rate.

11. The process of forming a homogenea continuous fabric consisting inmixing bronze powder with a film-forming solution, agitating the mixtureuntil substantially all 0 the bronze powder is suspended by'thesolution, continuing this suspension agitation during the dipping stepensuing, dipping the suspension while undergoing agitatlon, applyingcontinuously revolving film-forming surface on a line below thehorizontal axial plane on the rising quadrant of the revolving surface,circulating a current of preheated air over the film-coating so appliedto the revolving surface and in contact therewith for more than half itsrevolution, dried fihn therefrom while revolving.

I CARL P. OLSON.

and removing the 30

